This is actually a very interesting question for me. Is it true that you can be banned from an online casino like Stake for the only reason that you are winning too much?
I know it used to be a thing for some land based casinos in the past, but I don't think reputable online casinos of the level of Stake are practicing it these days. In fact, I'm pretty sure that all top online casinos don't do that.
I don't think you can really ban players for that as they do nothing wrong in fact.
They will probably just limit the players so they can only bet a low amount on the sports they always bet on. I got limited on a fiat only casino one time because I won like a bet of 100€ lol.
I don't think they would do that either. First off, you will never read in ToS of any reputable gambling site that winning too much results in some kind of limiting your bet amount. Secondly, you can bet a low amount many times and voila, you are betting big again, right?
That fiat based casino you were limited on for winning just €100 wasn't an example of a good casino, if you ask me.
On the contrary, the majority of casinos do limit their customers' accounts to make sure they don't win too much. All casinos are commercial operations in the business of making money, and if you consistently win their money, they will limit your ability to continue taking it from them. Even if they can't stop you from winning, they do have to do something if you are a consistently profitable customer.